Pipe Thickness calc. Query

http://cr4.globalspec.com/search/sitesearch?do=show&sort=textmatchrank&srch=pipe%20thickness&order=asc

See the following CR4 Thread(s): Piping-Standards-for-Calculating-Minimum-Wall-Thickness.

I used to work for 6 year in a pipe factory, good answer

Ing Galindo, Alberto

Actually my Question is--> during FEED stage I have some spec for which upto 2" pipe size the given thk if calc fits for the range,but my query for the sizes above 2 inch which needs to be calc.

What should be the general approach for Design Temp & Pressure consideration for calc. pipe thk?

shall we go for the range ?or shall we go as per line list design data?,if we go as per line list ,different lines will have different thk. for the same spec & same size as their design pressure & temp may vary.

I have seen the example in code they are showing up the example say design temp & pressure in CAESAR T1 & P1 which we normally take as per line list but not from Spec range.

If I have 6" pipe of particular spec. A106 Gr B material or any other as pers given spec. ,but having different Design pressure & Temp condition ,should my thickness vary(Do u agree to answer- Yes) ?but if I calc for P/T range with max pressure @ min temp. ,then the answer is NO

Is it appropriate to calc different thk for each condition of same spec lines or should we take the max /worst case Or should we go as per P/T range of spec.?or any specific thumb rule that we can go with Line list Design Data if the rating is too high e.g. 900# & above & below such rating we can use P/T rating to calc thk of pipe?

Can I get a Specific Answer like yes/no or which option to follow out of three possibilities as I mention, instead of Passing on the threads which after reading it also cannot conclude any answers?

pipe wall thickness shall be done on the basis of CLASS conditions..

class conditions would be given in PMS .

eg for class A .thickness is to be calculated on the basis of P/T range of this class.

Line list is for LINE condition and need not be used.

quiinces,

Can you pls clarify more,like what is class A mean & how to define class A & what are other classes?do we need to calculate thickness based on service temp for rating 600# and above classes